@inproceedings{CAAP-1991-Broek,
	author        = "P. M. van den Broek",
	booktitle     = "{Proceedings of the Fourth International Joint Conference on Theory and Practice of Software Development, Volume 1: Colloquium on Trees in Algebra and Programming}",
	doi           = "10.1007/3-540-53982-4_6",
	isbn          = "3-540-53982-4",
	pages         = "90--102",
	publisher     = "{Springer}",
	title         = "{Algebraic Graph Rewriting Using a Single Pushout}",
	year          = 1991,
}